BUN /Creatinine Ratio : 296

Test Code
BCRAU or 296


Alias/See Also
Blood Urea Nitrogen; BUN


CPT Codes
82565, 84520

Preferred Specimen
2 mL serum


Minimum Volume
1 mL


Other Acceptable Specimens
Spun SST tube


Transport Container
Serum separator tube (SST)


Transport Temperature
Room temperature


Specimen Stability
Room temperature: 7 days
Refrigerated: 5 days
Frozen: 28 days


Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Plasma


Methodology
See individual tests

Setup Schedule
Sunday - Saturday


Report Available
1 day


Reference Range
⁠⁠⁠⁠⁠⁠⁠Urea Nitrogen (BUN)
Age                      Male (mg/dL) Female (mg/dL)
 <1 Month             4-12                3-17
1-11 Months          2-13                4-14
1-3 Years              3-12                3-14
4-19 Years            7-20                7-20
≥20 Years             7-25                7-25

Creatinine
Age                       Male (mg/dL) Female (mg/dL)
≤2 days                    0.79-1.58      0.79-1.58
3-27 days                 0.35-1.23      0.35-1.23
1 month-9 years       0.20-0.73      0.20-0.73
10-12 years              0.30-0.78      0.30-0.78
13-15 years              0.40-1.05      0.40-1.00
16-17 years              0.60-1.20      0.50-1.00
18-29 years              0.60-1.24      0.50-0.96
30-39 years              0.60-1.26      0.50-0.97
40-49 years              0.60-1.29      0.50-0.99
50-59 years              0.70-1.30      0.50-1.03
60-69 years              0.70-1.35      0.50-1.05
70-79 years              0.70-1.28      0.60-1.00
≥80 years                 0.70-1.22      0.60-0.95
For patients >49 years of age, the upper reference limit for creatinine is approximately 13% higher for people identified as African-American.

eGFR ≥60 mL/min/1.73m2

Bun/Creatinine Ratio
<1 year Not Established
1-5 years 16-50 calc
6-10 years 13-36 calc
11-16 years 9-25 calc
≥17 years 6-22 calc


Clinical Significance
The BUN/Creatinine ratio is useful in the differential diagnosis of acute or chronic renal disease. Reduced renal perfusion, e.g., congestive heart failure, or recent onset of urinary tract obstruction will result in an increase in BUN/Creatinine ratio. Increased urea formation also results in an increase in the ratio, e.g., gastrointestinal bleeding, trauma, etc. When there is decreased formation of urea as seen in liver disease, there is a decrease in the BUN/Creatinine ratio. In most cases of chronic renal disease the ratio remains relatively normal.


Performing Laboratory
med fusion



The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.